Treating back pain by re-establishing the exchange of nutrient and waste

ABSTRACT

The intervertebral disc is avascular. With aging, endplates become occluded by calcified layers, and diffusion of nutrients and oxygen into the disc diminishes. The disc degenerates, and pain ensues. Conduits are delivered and deployed into the intervertebral disc to reestablish the exchange of nutrients and waste between the disc and bodily circulation to stop or reverse disc degeneration and relieve pain. The intervertebral disc installed with semi-permeable conduits may be used as an immuno-isolated capsule to encapsulate donor cells capable of biosynthesizing therapeutic molecules. The semi-permeable conduits establish the exchange of nutrients and therapeutic molecules between disc and bodily circulation to treat a disease without using immunosuppressive drugs.

FIELD OF INVENTION

This invention relates to methods and devices for transporting nutrientsand waste into and out of the intervertebral disc to halt or reverse thedegeneration of the intervertebral disc.

BACKGROUND

Low back pain is a leading cause of disability and lost productivity. Upto 90% of adults experience back pain at some time during their lives.For frequency of physician visits, back pain is second only to upperrespiratory infections. In the United States the economic impact of thismalady has been reported to range from $50-$100 billion each year,disabling 5.2 million people. Though the sources of low back pain arevaried, in many cases the intervertebral disc is thought to play acentral role. Degeneration of the disc initiates pain in other tissuesby altering spinal mechanics and producing non-physiologic stress insurrounding tissues.

The intervertebral disc 100 absorbs most of the compressive load of thespine, but the facet joints 142, 143 of the vertebral bodies 159 shareapproximately 16%. The disc 100 consists of three distinct parts: thenucleus pulposus 128, the annular layers and the cartilaginous endplates105, as shown in FIGS. 1 and 2. The disc 100 maintains its structuralproperties largely through its ability to attract and retain water. Anormal disc 100 contains 80% water in the nucleus pulposus 128. Thenucleus pulposus 128 within a normal disc 100 is rich in water absorbingsulfated glycosaminoglycans, creating the swelling pressure to providetensile stress within the collagen fibers of the annulus. The swellingpressure produced by high water content is crucial to supporting theannular layers for sustaining compressive loads, as shown in alongitudinal view in FIG. 2.

In adults, the intervertebral disc 100 is avascular. Survival of thedisc cells depends on diffusion of nutrients from external blood vessels112 and capillaries 107 through the cartilage 106 of the endplates 105,as shown in FIG. 2. Diffusion of nutrients also permeates fromperipheral blood vessels adjacent to the outer annulus, but thesenutrients can only permeate up to 1 cm into the annular layers of thedisc 100. An adult disc can be as large as 5 cm in diameter, hencediffusion through the cranial and caudal endplates 105 is crucial formaintaining the health of the nucleus pulposus 128 and inner annularlayers of the disc 100.

Calcium pyrophosphate and hydroxyapatite are commonly found in theendplate 105 and nucleus pulpous 128. As young as 18 years of age,calcified layers 108 begin to accumulate in the cartilaginous endplate105, as shown in FIG. 3. The blood vessels 112 and capillaries 107 atthe bone-cartilage interface are gradually occluded by the build-up ofthe calcified layers 108, which form into bone. Bone formation at theendplate 105 increases with age.

When the endplate 105 is obliterated by bone, diffusion between thenucleus pulposus 128 and blood vessels 112 beyond the endplate 105 isgreatly limited. In addition to hindering the diffusion of nutrients,calcified endplates 105 further limit the permeation of oxygen into thedisc 100. Oxygen concentration at the central part of the nucleus 128 isextremely low. Cellularity of the disc 100 is already low compared tomost tissues. To obtain necessary nutrients and oxygen, cell activity isrestricted to being on or in very close proximity to the cartilaginousendplate 105. Furthermore, oxygen concentrations are very sensitive tochanges in cell density or consumption rate per cell.

The supply of sulfate into the nucleus pulposus 128 for biosynthesizingsulfated glycosaminoglycans is also restricted by the calcifiedendplates 105. As a result, the sulfated glycosaminoglycan concentrationdecreases, leading to lower water content and swelling pressure withinthe nucleus pulposus 128. During normal daily compressive loading on thespine, the reduced pressure within the nucleus pulposus 128 can nolonger distribute the forces evenly along the circumference of the innerannulus to keep the lamellae bulging outward. As a result, the innerlamellae sag inward, while the outer annulus continues to bulge outward,causing delamination 114 of the annular layers, as shown in FIGS. 3 and4.

The shear stresses causing annular delamination and bulging are highestat the posteriolateral portions adjacent to the neuroforamen 121. Thenerve 194 is confined within the neuroforamen 142 between the disc andthe facet joint 142, 143. Hence, the nerve 194 at the neuroforamen 121is vulnerable to impingement by the bulging disc 100 or bone spurs.

When oxygen concentration in the disc falls below 0.25 kPa (1.9 mm Hg),production of lactic acid dramatically increases with increasingdistance from the endplate 105. The pH within the disc 100 falls aslactic acid concentration increases. Lactic acid diffuses throughmicro-tears of annulus irritating the richly innervated posteriorlongitudinal ligament 195, facet joint and/or nerve root 194. Studiesindicate that lumbar pain correlates well with high lactate levels andlow pH. The mean pH of symptomatic discs was significantly lower thanthe mean pH of the normal discs. The acid concentration is three timeshigher in symptomatic discs than normal discs. In symptomatic discs withpH 6.65, the acid concentration within the disc is 5.6 times the plasmalevel. In some preoperative symptomatic discs, nerve roots 194 werefound to be surrounded by dense fibrous scars and adhesions withremarkably low pH 5.7-6.30. The acid concentration within the disc was50 times the plasma level.

Approximately 85% of patients with low back pain cannot be given aprecise pathoanatomical diagnosis. This type of pain is generallyclassified under “non-specific pain”. Back pain and sciatica can berecapitulated by maneuvers that do not affect the nerve root, such asintradiscal saline injection, discography, and compression of theposterior longitudinal ligaments. It is possible that some of thenon-specific pain is caused by lactic acid irritation secreted from thedisc. Injection into the disc can flush out the lactic acid. Maneuveringand compression can also drive out the irritating acid to producenon-specific pain. Currently, no intervention other than discectomy canhalt the production of lactic acid.

The nucleus pulposus 128 is thought to function as “the air in a tire”to pressurize the disc 100. To support the load, the pressureeffectively distributes the forces evenly along the circumference of theinner annulus and keeps the lamellae bulging outward. The process ofdisc degeneration begins with calcification of the endplates 105, whichhinders diffusion of sulfate and oxygen into the nucleus pulposus 128.As a result, production of the water absorbing sulfatedglycosaminoglycans is significantly reduced, and the water contentwithin the nucleus decreases. The inner annular lamellae begin to saginward, and the tension on collagen fibers within the annulus is lost.The degenerated disc 100 exhibits unstable movement, similar to a flattire. Approximately 20-30% of low-back-pain patients have been diagnosedas having spinal segmental instability. The pain may originate fromstress and increased load on the facet joints and/or surroundingligaments. In addition, pH within the disc 100 becomes acidic from theanaerobic production of lactic acid, which irritates adjacent nerves andtissues.

Resilient straightening of a super elastically curved needle within arigid needle is described in prior art DE 44 40 346 A1 by Andres Melzerfiled on Nov. 14, 1994 and FR 2 586 183-A1 by Olivier Troisier filed onAug. 19, 1985. The curved needles of these prior art are used to deliverliquid into soft tissue. In order to reach the intervertebral discwithout an external incision, the lengths of the curved and rigidneedles must be at least six inches (15.2 cm). There are multipleproblems when attempting to puncture the calcified endplate as describedin the prior art. Shape memory material for making the curved needleusually is elastic. Nickel-titanium alloy has Young's modulusapproximately 83 GPa (austenite), 28-41 GPa (martensite). Even if thehandles of both the curved and rigid needles are restricted fromtwisting, the long and elastically curved needle 101 is likely to twistwithin the lengthy rigid needle 220 during endplate 105 puncturing, asshown in FIGS. 54 and 55. As a result, direction of puncture is likelyto be deflected and endplate 105 puncture would fail.

Furthermore, in the prior art, the sharp tips of their rigid needles areon the concave sides of the curved needles. When puncturing a relativelyhard tissue, such as calcified endplates 105, the convex sides of thecurved needles are unsupported and vulnerable to bending, resulting infailure to puncture through the calcified endplates 105. To minimizebending or twisting, the sizes of their curved and rigid needles arerequired to be large. By increasing the sizes of the curved 101 andrigid 220 needles, friction between the curved 101 and rigid 220 needlesgreatly increases, making deployment and retrieval of the curved needle101 very difficult. In addition, a large opening created in the disc 100by the large needles may cause herniation of the nucleus pulposus 128.Similarly, a large opening at the endplate 105 may cause Schmorl'snodes, leakage of nucleus pulpous 128 into the vertebral body 159.

In essence, the support from the distal end of the rigid needle 220 inFIGS. 62-67 of this invention is relevant to support puncturing of arelatively hard tissue, such as calcified endplate 105 with a smalldiameter needle 101. Furthermore, the non-round cross-sections of thecurved 101 and rigid 220 needles in FIGS. 56-60 to prevent twisting arealso relevant to ensure successful puncturing through the calcifiedendplate 105.

SUMMARY OF INVENTION

In this invention, conduits are delivered through the calcifiedendplates to re-establish the exchange of nutrients and waste betweenthe disc and vertebral bodies. The conduit is delivered within anelastically curved needle. The curved needle is resiliently straightenedwithin a rigid needle. The rigid needle punctures into a degeneratingdisc with calcified endplates. The elastically curved needle carryingthe conduit is then deployed from the rigid needle to resume the curvedconfiguration and puncture through the calcified endplate. By retrievingthe curved needle back into the rigid needle while holding a plungerbehind the conduit stationary, the conduit is deployed across theendplate to transport nutrients and waste between the disc and vertebra.

The puncturing device in this invention is designed to minimize twistingand friction between the curved and rigid needles. The device alsoprovides support to the elastically curved needle to minimize bendingduring endplate puncturing. In addition, the device is designed todeliver at least one conduit at the endplate to bridge between theavascular intervertebral disc and the vertebral body for exchange ofnutrients, oxygen, carbon dioxide, lactate and waste.

Nutrients and oxygen are abundantly supplied by peripheral blood vesselsnear the outer annulus. Conduits can also be deployed transverse thedegenerating disc to draw nutrients from the outer annulus into thenucleus pulposus to halt disc degeneration.

After nutrient and waste exchange is re-established by thesemi-permeable conduits, stem cells, growth factor or gene therapeuticagents can be injected into the disc to promote regeneration. Inaddition, the disc with semi-permeable conduits is still immunoisolated.Donor cells injected into the disc can be nourished by nutrients throughthe semi-permeable conduits without triggering an immune response. Thesecells are selected for their capability to biosynthesize therapeuticagents, such as insulin and neurotransmitters. The therapeutic agentsare transported through the semi-permeable conduits into bodycirculation to treat a disease.

REFERENCE NUMBER

-   100 Intervertebral disc-   101 Needle-   102 Bevel or tapering-   103 Trocar-   104 Lumen or channel of conduit-   105 Endplate-   106 Hyaline cartilage-   107 Capillaries-   108 Blockade or calcified layers-   109 Plunger-   110 Monofilament-   112 Blood vessels-   113 Tissue gripping flange-   114 Annular delamination-   115 Epiphysis-   116 Penetration marker-   121 Neuroforamen-   122 Braided multi-filament-   123 Spinal cord-   124 Porous conduit-   125 Tube-   126 Conduit-   127 Electronic cutter or laser-   128 Nucleus pulposus-   129 Facet joint-   130 Handle of curve needle-   131 Guide rail of curve needle handle-   132 Handle of rigid sleeve-   133 Track of rigid sleeve handle-   134 Electronic cutting device-   135 Electric cord-   140 Sacrum-   142 Superior articular process-   143 Inferior articular process-   153 Label indicating curved direction-   159 Vertebral body-   160 Tissue ingrowth indentation-   161 Knot-   162 Protrusion or ring-   163 Coating-   184 Impingement-   193 Psoas muscle-   194 Nerve root-   195 Posterior longitudinal ligament-   121 Neuroforamen-   217 Screw entry-   220 Rigid sleeve or needle-   224 Puncture-   230 Dilator-   268 Lumen of rigid sleeve-   269 Lumen of rigid needle-   270 Window of rigid sleeve-   271 Shape memory extension-   272 Ramp in lumen of rigid needle-   276 Syringe-   277 Donor cells

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a healthy disc 100 with normal swelling pressure withinthe nucleus pulposus 128 to support the layers of annulus duringcompressive loading.

FIG. 2 shows a longitudinal view of a spine segment, displaying outwardbulging of annular layers during compression of a healthy disc 100between cartilaginous 106 endplates 105.

FIG. 3 shows that the calcified layers 108 of the endplates 105 hinderdiffusion of nutrients between the inner disc 100 and the vertebralbodies 159, leading to inward bulging and annular delamination 114.

FIG. 4 depicts a degenerated and flattened disc with reduced swellingpressure within the nucleus pulposus 128 and annular delamination.

FIG. 5 depicts trocar 103 insertion into the disc 100 using the guidingtechnique similar to that used in discography.

FIG. 6 shows insertion of a dilator 230 over the trocar 103.

FIG. 7 depicts withdrawal of the trocar 103. The dilator 230 acts as apassage leading into the disc 100.

FIG. 8 shows a longitudinal view of the degenerated spinal segment withinsertion of the dilator 230.

FIG. 9 depicts an elastically curved needle 101.

FIG. 10 shows the elastic needle 101 being resiliently straightenedwithin a rigid sleeve 220.

FIG. 11 shows a round cross-section of the needle 101 within the rigidsleeve 220.

FIG. 12 depicts insertion of the resiliently straightened needle 101within the rigid sleeve 220 into the dilator 230 leading into the disc100.

FIG. 13 shows a longitudinal view of the needle 101 and sleeve 220assembly inserted into the dilator 230 leading into the disc 100.

FIG. 14 depicts upward puncturing of the needle 101 into the endplate105 (not shown) by deploying the resiliently straightened needle 101from the rigid sleeve 220.

FIG. 15 shows endplate 105 puncturing through the calcified layers 108by deploying the curved needle 101 from the rigid sleeve 220.

FIG. 16 depicts permeation of water, nutrients and metabolites throughthe puncture sites 224 of the superior and inferior endplates 105.

FIG. 17 depicts re-establishment of swelling pressure by the renewedbiosynthesis of glycosaminoglycan within the nucleus pulposus 128.

FIG. 18 depicts an electronic device 134 empowering a cutter 127 topuncture, drill, abrade or cauterize through the calcified endplate 105.

FIG. 19 depicts a conduit 126 in the form of an elastic tube 125 withtissue-holding flanges 113 and longitudinal opening 104.

FIG. 20 shows insertion of the elastic tube 125 onto the elasticallycurved needle 101 with a sliding plunger 109 abutting the tube 125.

FIG. 21 depicts the needle 101 caring the elastic tube 125 beingresiliently straightened within the rigid sleeve 220.

FIG. 22 shows insertion of the needle 101, elastic tube 125, sleeve 220and plunger 109 into the dilator 230.

FIG. 23 depicts deployment of the needle 101 delivering the tube 125through the calcified layer 108 of the endplate 105.

FIG. 24 shows withdrawal of the needle 101 while holding the plunger 109stationary to dislodge the tube 125 from the needle 101.

FIG. 25 shows the lower portion of the tube 125 dislodged within thenucleus pulposus 128 and the top portion deployed within the cranialvertebral body 159 (not shown) through the endplate 105 (also notshown).

FIG. 26 depicts stacking of a square handle 130 of the curved needle 101within a handle 132 of the rigid sleeve 220 to avoid rotation betweenthe needle 101 and sleeve 220.

FIG. 27 depicts a handle 130 of the elastically curved needle 101,containing guide rails 131 and an orientation line 153 to show thedirection of the curvature.

FIG. 28 shows tracks 133 on a handle 132 of the rigid sleeve 220 withorientation line 153 and penetration markers 116.

FIG. 29 depicts the assembly with the rails 131 in the tracks 133 toavoid rotation between the needle 101 and the sleeve 220.

FIG. 30 shows resumption of the curvature as the elastically curvedneedle 101 is deployed from the rigid sleeve 220.

FIG. 31 shows oval cross-sections of the needle 101 and the rigid sleeve220 to prevent rotation between the needle 101 and sleeve 220.

FIG. 32 indicates square cross-sections of the needle 101 within thesleeve 220.

FIG. 33 depicts rectangular cross-sections of the needle 101 within thesleeve 220.

FIG. 34 shows triangular cross-sections of the needle 101 within thesleeve 220.

FIG. 35 depicts a conduit 126 made as a small tube 125 with alongitudinal channel 104.

FIG. 36 indicates a conduit 126 made as a braided tube 125 with alongitudinal channel 104.

FIG. 37 shows a conduit 126 made with porous material in a tubular form125.

FIG. 38 depicts a conduit 126 made as a braided suture 122 or braidedthread 122.

FIG. 39 indicates a conduit 126 made with a flexible porous or spongyfiber 124.

FIG. 40 shows a conduit 126 abutting against a plunger 109 within alumen 269 of an elastically curved needle 101.

FIG. 41 shows a bevel 102 at the distal end of the lumen 268 of therigid sleeve 220 to minimize friction during deployment and retrieval ofthe curved needle 101.

FIG. 42 depicts the elastically curved needle 101 with the conduit 126being resiliently straightened within a rigid sleeve 220.

FIG. 43 indicates insertion of the assembly containing the needle 101,conduit 126, plunger 109 and sleeve 220 into a dilator 230.

FIG. 44 shows deployment of the curved needle 101 through the calcifiedendplate 105.

FIG. 45 depicts dislodgement of the conduit 126 by withdrawing theneedle 101 while holding the plunger 109 stationary.

FIG. 46 depicts insertion of the needle 101, conduit 126, plunger 109and sleeve 220 assembly into the dilator 230 leading into disc 100.

FIG. 47 shows deployment of the curved needle 101 through the calcifiedendplate 105.

FIG. 48 depicts withdrawal of the needle 101 while the plunger 109 isheld stationary to dislodge the conduit 126 through the calcifiedendplate 105.

FIG. 49 shows a portion of the conduit 126 within the nucleus pulposus128 and the remaining portion within the vertebral body through theendplate (not shown).

FIG. 50 depicts two conduits 126 within the lumen 269 of the needle 101.

FIG. 51 shows deployment of two conduits 126 through superior andinferior calcified endplates 105.

FIG. 52 indicates disc 100 height restoration from regained swellingpressure within the nucleus pulposus 128 following the reestablishmentof nutrient and waste exchange.

FIG. 53 depicts two conduits 126 extending from the nucleus pulposus 128into superior and inferior vertebral bodies 159 through the calcifiedendplates 105 (not shown).

FIG. 54 depicts twisting of the curved needle 101 within the rigidsleeve 220 during endplate 105 puncturing. The cross-section is shown inFIG. 62.

FIG. 55 shows the cross-sectional view of FIG. 61. The elastic needle101 twists or rotates within the rigid sleeve 220.

FIG. 56 depicts prevention of twisting by using a needle 101 and sleeve220 with elliptical cross-sections.

FIG. 57 shows a cross-sectional view of the elliptical needle 101 withinthe elliptical sleeve 220, depicted in FIG. 63, to limit rotationalmovement FIG. 58 indicates a square cross-section of the needle 101 andsleeve 220.

FIG. 59 indicates a rectangular cross-section of the needle 101 andsleeve 220.

FIG. 60 indicates a triangular cross-section of the needle 101 andsleeve 220.

FIG. 61 depicts bending or drooping of the curved needle 101 duringendplate 105 puncturing.

FIG. 62 shows a sharpened end or tip of the rigid needle 220 providingsupport beneath the convex side of the curved needle 101 to reducebending or drooping during puncturing.

FIG. 63 depicts an extended distal end of the rigid needle 220 tolengthen the support beneath the convex side of the curved needle 101during endplate 105 puncturing.

FIG. 64 shows a window 270 near the distal end of a sleeve 220 with anelliptical cross-section. The distal portion of the window 270 isslanted or sloped to conform to the curved needle 101.

FIG. 65 depicts the sharp tip of the elastically curved needle 101located on the concave side of the curvature for ease of protrusionthrough the window 270.

FIG. 66 shows support of the convex side of the curved needle 101 by thedistal pocket of the window 270 to strengthen the needle 101 to punctureendplate 105.

FIG. 67 shows a rigid needle 220 with the window 270.

FIG. 68 depicts the elastically curved needle 101 within a curved shapememory extension 271. Both curved needle 101 and extension 271 arehoused within a rigid sleeve 220.

FIG. 69 shows resilient straightening of the shape memory extension 271within the rigid sleeve 220.

FIG. 70 shows endplate 105 puncturing by the fortified curved needle 101without increasing the size of the endplate 105 puncture.

FIG. 71 shows a sharpened shape memory extension 271 to support endplate105 puncturing.

FIG. 72 shows a longitudinal cross section of a curved needle 101 withnon-uniform outer diameter, supported by a ramp 272 within the lumen 268of the rigid needle 220.

FIG. 73 depicts a conduit 126 containing a multi-filament 122 sectionand a tubular 125 section.

FIG. 74 shows a multi-filament 122 with a tube 125 at the mid-portion toprevent mineralization or clotting, especially around the endplate 105.

FIG. 75 depicts a monofilament 110 within the multi-filament 122 toassist deployment

FIG. 76 shows degradable tubes (shaded) 125 covering both ends of amulti-filament 122 to prevent bunching during deployment from the curvedneedle 101.

FIG. 77 shows the needle 101 carrying the conduit 126 transverse thedegenerating disc 100.

FIG. 78 depicts a longitudinal view of FIG. 84 to deliver a conduit 126transverse a degenerating disc 100.

FIG. 79 depicts withdrawal of the needle 101 while holding the plunger109 stationary to deploy or dislodge the conduit 126 within thedegenerating disc 100.

FIG. 80 depicts drawing of nutrients from the outer annulus into thenucleus pulposus 128 through capillary action or convection flow withinthe conduit 126.

FIG. 81 depicts a radiopaque, echogenic or magnetic coating 163 on theneedle 101 to indicate the location of the conduit 126 within the needle101.

FIG. 82 shows two conduits 126 inserted through the disc 100 to exchangenutrients and waste between the outer annulus and the nucleus pulposus128.

FIG. 83 depicts the distal tip of the needle 101 penetrating beyond theintervertebral disc 100.

FIG. 84 shows the length of the conduit 126 extending beyond the disc100 to maximize exchange of nutrients and waste.

FIG. 85 depicts restoration of swelling pressure within the nucleuspulposus 128 enabling it to sustain compressive loading.

FIG. 86 shows a conduit 126 extending into the Psoas major muscle 193for nutrient and waste exchange to nourish and/or regenerate the disc100.

FIG. 87 depicts two conduits 126 extending into both Psoas major muscles193 to expedite nutrient and waste exchange to nourish and/or regeneratethe disc 100.

FIG. 88 depicts a series of knots 161 tied on a multi-filament 122 toprevent or minimize conduit 126 migration with time.

FIG. 89 shows rings 162 or protrusions on the conduit 126 to prevent orminimize migration with time.

FIG. 90 shows indentations 160 to promote tissue ingrowth and prevent orminimize conduit 126 migration with time.

FIG. 91 shows injection of donor cells 277 through a syringe 276 into adisc 100 containing conduits 126 through cranial and caudal endplates105.

FIG. 92 shows injection of donor cells 277 through a syringe 276 into adisc 100 with conduits 126 transverse the disc 100 and extending intomuscles 193.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Since diffusion from the endplate 105 is crucial for maintaining theintervertebral disc, effort is made to reestablish nutrient and wasteexchange between the nucleus pulposus and circulation within thevertebral body. Guided by anteroposterior and lateral views fromfluoroscopes, a trocar 103 enters posteriolaterally, 45° from mid-lineinto the disc 100, as shown in FIG. 5. This guiding technique is similarto the one used in diagnostic injection of radiopaque dye fordiscography or chymopapain injection for nucleus pulposus digestion. Adilator 230 is inserted over the trocar 103, as shown in FIG. 6. Thetrocar 103 is then withdrawn. The dilator 230 remains as a passageleading into the disc 100, as shown in FIG. 7. FIG. 8 shows the distalend of the dilator 230 near the nucleus pulposus 128 of the degeneratingdisc 100.

An elastically curved needle 101, as shown in FIG. 9, is resilientlystraightened in a rigid sleeve 220 indicated in FIG. 10. The round crosssection of the straightened needle 101 and sleeve 220 is shown in FIG.11. The resiliently straightened needle 101 within the rigid sleeve 220is inserted into the dilator 230 and the disc 100, as shown in FIG. 12.A longitudinal view of the needle 101 insertion into the degeneratingdisc 100 is indicated in FIG. 13. The elastically curved needle 101 isdeployed by holding the rigid sleeve 220 stationary while pushing theneedle 101 inward. The needle 101 resumes the curved configuration as itexits the distal opening of the sleeve 220, puncturing upward as shownin FIG. 14, through the cartilage 106 and calcified layers 108 into thevertebral body 159, as indicated in FIG. 15.

Multiple endplate 105 punctures 224 can be accomplished to re-establishthe exchange of nutrients and waste between the disc 100 and bodilycirculation. After retrieving the elastically curved needle 101 into thesleeve 220, the assembly of needle 101 and sleeve 220 can be furtheradvanced into or slightly withdrawn from the disc 100 to puncture moreholes 224 through the calcified cranial endplate 105. By tuning theassembly of needle 101 and sleeve 220 180°, the caudal endplate 105 canalso be punctured, as shown in FIG. 16, to re-establish the exchange ofnutrients, oxygen and waste through the superior and inferior endplates105. FIG. 17 indicates restoration of swelling pressure within thenucleus pulposus 128 enabling the disc 100 to sustain compressive loads.With the presence of oxygen within the disc 100, production of lacticacid may also decrease and ease chemical irritation and pain.

Endplate 105 puncturing can also be accomplished by electronic devices134, such as a laser, cutting or abrading device. FIG. 18 depicts anelectronic device 134 powering a cutter 127 to puncture, drill, abradeor cauterize the endplate 105 to re-establish the exchange of nutrientsand waste. The electronic device 134 can be a cautery, laser, or drill.

Re-establishing the exchange of nutrients and waste through thecalcified endplate 105 can also be accomplished using a conduit 126. Aconduit 126 can be an elastic tube 125 with a lumen or channel 104 andtissue-holding flanges 113 at both ends, as shown in FIG. 19. Theorientations of the flanges 113 located at both ends of the conduit 126are counter gripping to anchor onto the endplate 105. The tube 125 isinserted over the elastically curved needle 101 and abutting a slidingplunger 109, as shown in FIG. 20. The needle 101 carrying the elastictube 125 is resiliently straightened within the rigid sleeve 220, asdepicted in FIG. 21. The assembly of the straightened needle 101, tube125, sleeve 220 and plunger 109 is inserted into the dilator 230, asshown in FIG. 22, and into the disc 100. As the resilient needle 101carrying the tube 125 is deployed from the rigid sleeve 220, thecurvature of the needle 101 resumes and punctures through the calcifiedendplate 105, as shown in FIG. 23. The needle 101 is withdrawn while theplunger 109 is held stationary to dislodge the tube 125 from the needle101 into the endplate 105, as shown in FIG. 24. The lumen 104 of thetube 125 acts as a passage for exchanging nutrients, gases and wastebetween the vertebral body 159 and the inner disc 100. A portion of thetube 125 is in the nucleus pulposus 128 or inner disc 100, while theremaining portion is within the vertebral body (not shown) in FIG. 25.

The handle 130 of the curved needle 101 and the handle 132 of the rigidsleeve 229 are used to maintain the direction of needle 101 deployment.The square handle 130 of the curved needle 101 is stacked within thehandle 132 of the rigid sleeve 220, as shown in FIG. 26, to avoidrotation between the needle 101 and sleeve 220. The handle 130 of theneedle 101 can also contain guide rails 131, as shown in FIG. 27. Theguide rails 131 are sized and configured to fit within the sunken tracks133 on the handle 132 of the rigid sleeve 220, as indicated in FIG. 28.Direction of the needle's curvature is indicated by the orientationlines 153 on the handle 130 of the needle 101, as shown in FIG. 27, andon the rigid sleeve 220 as shown in FIG. 28. To indicate depth ofinsertion into the body, penetration markers 116 are labeled on thesleeve 220, as shown in FIG. 28. The guide rails 131 within the tracks133 keep the handles 130, 132 from rotating around each other, as shownin FIG. 29. As the resiliently straightened needle 101 advances andprotrudes from the rigid sleeve 220, the curvature of the needle 101resumes, as shown in FIG. 30. Since the handle 130 of the needle 101 andthe handle 132 of the sleeve 220 are guided by the rails 131 in tracks133, the direction of needle 101 puncturing is established andpredictable for the operator or surgeon.

Non-circular cross-sections of the needle 101 and rigid sleeve 220 canalso prevent rotation. FIG. 31 shows a needle 101 and a sleeve 220 withoval cross-section. FIG. 32 indicates a square cross-section. FIG. 33depicts a rectangular cross-section. FIG. 34 shows a triangularcross-section.

Conduits 126 can also be made small enough to fit within the lumen ofthe elastically curved needle 101. A conduit 126 can be a small tube 125with a longitudinal channel 104, as shown in FIG. 35, for transportingnutrients, oxygen and waste dissolved in fluid. The tubular conduit 126with a lumen 104 can be braided or weaved with filaments, forming aporous material as shown in FIG. 36. Filament is a fine thread, fiber orthread-like structure. The fluid can be transported through the lumen104 as well as permeated through the braided filaments of the tube 125.The tubular conduit 126 can also be molded or extruded, forming a porousor spongy material, as shown in FIG. 37, to transport nutrients, oxygenand waste dissolved in fluid through the lumen 104 as well as throughthe pores.

Nutrients, oxygen, lactate, metabolites, carbon dioxide and waste canalso be transported in fluid through capillary action of the conduit,made with a porous or channeled material, into tubular, multi-filamentsor braided filaments 122, as shown in FIG. 38. The conduit 126 may notrequire the longitudinal lumen 104 as mentioned. A strand of braidedfilaments 122 can be a suture with channels formed among weavings of thefilaments, capable of transporting fluid with nutrients, gases andwaste. The braided filaments 122 can be coated with a stiffening agent,such as starch, to aid deployment using the plunger 109. Similar to thechannels formed by the braided filaments 122, a conduit 126 made as aspongy thread 124, as shown in FIG. 39, can also transport fluid withnutrients, gases and wastes through the pores and channels formed withinthe porous structure of the material.

A conduit 126 is inserted into a longitudinal opening 269 of anelastically curved needle 101 abutting a plunger 109, as shown in FIG.40. To minimize friction between the curved needle 101 and the rigidsleeve 220, the distal end of the lumen 268 of the sleeve 220 is angledor tapered with a bevel 102 or an indentation, conforming to the concavecurvature of the needle 101, as shown in FIG. 41. A lubricant or coatingto lower friction can also be applied on the surface of the elasticallycurved needle 101 and/or within the lumen 268 of the rigid sleeve 220.The elastically curved needle 101 carrying the conduit 126 isresiliently straightened within a rigid sleeve 220, as shown in FIG. 42.The assembly is then inserted into a dilator 230, as indicated in FIG.43, which leads into the disc 100. As the resiliently straightenedneedle 101 is deployed from the sleeve 220, the needle 101 carrying theconduit 126 resumes the curved configuration and punctures into thecartilaginous endplate 105 through the calcified layers 108, as shown inFIG. 44. The elastically curved needle 101 is then retrieved into thesleeve 220 while the plunger 109 is held stationary to deploy theconduit 126 at the calcified endplate 105, as shown in FIG. 45. Insummary, the conduit 126 has a first end and a second end, and thedeployment device of the conduit 126 has two positions. In the firstposition, the conduit 126 is located at least partially within theneedle 101, as shown in FIGS. 40-44, 46-47, 72, 78 and 83. In the secondposition, the conduit 126 is deployed or expelled from the needle 101,with the first end of the conduit in the intervertebral disc 100 and thesecond end in bodily circulation. The conduit 126 bridges, taps, linksor connects between the intervertebral disc 100 and bodily circulationin the vertebral body 159 or muscle 193, as shown in FIGS. 45, 48, 79and 84-87. As a result, transport of waste in the disc 100 and nutrientsin bodily circulation is re-established to alleviate back pain andregenerate the avascular disc 100, as shown in FIGS. 51-53 and 85-87.

FIG. 46 depicts insertion of the needle 101, conduit 126, plunger 109,sleeve 220 and dilator 230 into the disc 100. The resilientlystraightened needle 101 carrying the conduit 126 is deployed from thesleeve 220, resumes the curvature and punctures through the endplate 105and calcified layers 108, as shown in FIG. 47. While the plunger 109behind the conduit 126 is held stationary, the elastically curved needle101 is withdrawn from the calcified endplate 105 and retrieved into thesleeve 220 to deploy, expel or dislodge the conduit 126 at the calcifiedendplate 105, as shown in FIG. 48. The conduit 126 acts as a channel ora passage, bridging between the bone marrow of the vertebral body 159and the disc 100 to re-establish the exchange of fluid, nutrients, gasesand wastes. FIG. 49 shows the general location of the conduit 126between the disc 100 and the vertebral body through the calcifiedendplate (both not shown).

Multiple conduits 126 can be loaded in series into the curved needle101, as shown in FIG. 50. Each conduit 126 is deployed sequentially atthe calcified endplate 105 by retrieving the curved needle 101 andholding the plunger 109 stationary. In essence, the plunger 109 isadvanced toward the distal end of the needle 101 one conduit-length at atime. After deploying the first conduit 126 at the cranial endplate 105,the rigid sleeve 220 is rotated 180° to deploy the second conduit 126into the caudal endplate 105, as shown in FIG. 51. Multiple conduits 126within the elastically curved needle 101 allow surgeons to implantmultiple conduits through calcified endplates 105 without having towithdraw the needle 101 assembly, reload additional conduits 126 andre-insert the assembly into the disc 100.

In the supine position, disc pressure is low. During sleep, fluid isdrawn in by the water absorbing glycosaminoglycans within the nucleuspulposus 128. By bridging the calcified endplate 105, theglycosaminoglycans draw fluid with sulfate, oxygen and other nutrientsthrough the conduits 126 into the nucleus pulposus 128 during sleep by(1) capillary action, and (2) imbibing pull of the water-absorbingglycosaminoglycans. The flow of sulfate, oxygen and nutrients ischanneled within the conduit 126 unidirectionally toward the nucleuspulposus 128, rather than via the dispersion mechanism in diffusion.

It is generally accepted that disc 100 degeneration is largely relatedto nutritional and oxygen deficiency. By re-establishing the exchange, arenewed and sustained supply of sulfate may significantly increase theproduction of sulfated glycosaminoglycans and restore swelling pressure.Restoration of swelling pressure within the nucleus pulposus 128reinstates the tensile stresses within the collagen fibers of theannulus, thus reducing the inner bulging and shear stresses between thelayers of annulus, as shown in FIG. 52. Similar to a re-inflated tire,disc 100 bulging is reduced and nerve impingement is minimized. Thus,the load on the facet joints 129 is also reduced to ease pain, themotion segment is stabilized, and disc 100 space narrowing may cease.The progression of spinal stenosis is halted and/or reversed, as shownin FIG. 53 to ease pain.

In daily activities, such as walking and lifting, pressure within thedisc 100 greatly increases. Direction of the convective flow thenreverses within the conduit 126, flowing from high pressure within thedisc 100 to low pressure within vertebral bodies 159. The lactic acidand carbon dioxide dissolved in the fluid within the nucleus pulposus128 is slowly expelled through the conduit 126 into the vertebral bodies159, then to bodily circulation. As a result, the lactic acidconcentration decreases, and pH within the disc 100 is normalized.

Furthermore, due to the abundance of oxygen in the disc 100 suppliedthrough the conduit 126, lactic acid normally produced under anaerobicconditions may drastically decrease. Hence, the pain caused by acidicirritation at tissues, such as the posterior longitudinal ligament 195,superior 142 and inferior 143 articular processes of the facet joint,shown in FIG. 53, is anticipated to quickly dissipate. Buffering agents,such as bicarbonate, carbonate or others, can be loaded or coated on theconduits 126 to neutralize the lactic acid upon contact andspontaneously ease the pain.

The elasticity of the curved needle 101 still can twist within the rigidsleeve 220 during endplate 105 puncturing, as shown in FIG. 54. Thelikelihood of twisting increases with the length of the elastic needle101. The twisting is depicted in a cross-sectional view of the sleeve220, needle 101 and conduit 126 in FIG. 55. The elastic twisting betweenthe shafts of the needle 101 and sleeve 220 allows directional shift atthe tip of the needle 101 during contact with the calcified endplate105. As a result, puncturing of the endplate 105 may fail.

To avoid twisting, the cross-sections of the needle 101 and sleeve 220can be made non-round, such as oval in FIG. 56 with a cross-sectionalview in FIG. 57. A square cross-section is shown in FIG. 58. Arectangular cross-section is shown in FIG. 59. A triangularcross-section is in FIG. 60.

The elastic property of the curved needle 101 may bend and fail topenetrate through the calcified endplate 105, as shown in FIG. 61. Thedirection of the bend or droop is at the convex side of the curvature ofthe needle 101. To minimize the droop, the distal end of the rigidsleeve 220 is cut at an angle, providing an extension to support theconvex side of the curved needle 101 during endplate 105 puncturing, asshown in FIG. 62. The angled cut of the rigid sleeve 220 functions as arigid needle 220 with a sharp tip supporting the convex side of thecurved needle 101, as shown in FIG. 62. The supporting structure can befurther extended by cutting an indentation near the distal end of therigid needle 220, as shown in FIG. 63, to increase support of the convexside of the curved needle 101 during endplate 105 puncturing.

To further support the elastically curved needle 101, a window 270 maybe located near the distal end of the rigid sleeve 220 with an ovalcross-section, as shown in FIG. 64. The distal side of the window 270 isopen slanted at an angle. The slant can also be formed with multipleangles into a semi-circular-like pocket, sized and configured to fit theconvex side of the elastically curved needle 101. FIG. 65 showsprotrusion of the elastically curved needle 101 from the window 270 ofthe rigid sleeve 220. The sharp tip of the curved needle 101 is locatedon the concave side of the curvature to avoid scraping or snagging onthe distal portion of the window 270 during deployment. FIG. 66 showsdeployment of the elastically curved needle 101 from the window 270 ofthe rigid sleeve 220. The semi-circular pocket of the distal window 270supports and brackets around the base of the convex curvature tominimize bending, twisting and/or deflection of the curved needle 101during endplate 105 puncturing. In essence, the slanted portion of thewindow 270 provides a protruded pocket to direct and support the curvedneedle 101. The distal end of the rigid sleeve 220 can be sharpened tofunction as a rigid needle 220 with the window 270, as shown in FIG. 67.

When a substantial amount of bone is formed, puncturing through the bonyendplate 105 with a small curved needle 101 can be challenging.Increasing the size of the needle 101 and creating a large hole 224 atthe endplate 105 may cause leakage of nucleus pulposus 128 into thevertebral bodies 159. To support a small curved needle 101, a shapememory extension 271 containing a curvature similar to the curved needle101 is added to strengthen and support the elastically curved needle101, as shown in FIG. 68. The shape memory extension 271 can beindented, as shown in FIG. 68, or tubular at the distal end. The curvedneedle 101 and shape memory extension 271 are capable of slidingindependently within the rigid sleeve or needle 220. FIG. 69 showsresiliently straightening of both the curved needle 101 and shape memoryextension 271 within the rigid sleeve 220. Both the curved needle 101and shape memory extension 271 apply stresses on the rigid sleeve 220.To minimize potential bending of the rigid sleeve 220, the stresses aredistributed over a larger area by positioning the tip of the needle 101proximal to the curvature of the shape memory extension 271, as shown inFIGS. 68-69. Spreading of the stresses also helps to ease the deploymentand retrieval of both the needle 101 and shape memory extension 271.

For tissue puncturing, the shape-memory extension 271 is deployed fromthe rigid sleeve 220, as shown in FIG. 68, followed by the curved needle101 gliding along the curvature of the shape-memory extension 271 andpuncturing into the calcified endplate 105, as shown in FIG. 70. Theshape memory extension 271 provides support to the needle 101 tominimize bending and twisting during puncturing without increasing thesize of the puncture. The shape memory extension 271 can also benon-indented and sharpened to facilitate tissue piercing, as shown inFIG. 71. To dislodge the conduit 126 at the endplate 105, the plunger109 behind the conduit 126 is held stationary, while the curved needle101 is retrieved into the shape memory extension 271. The shape memoryextension 271 is then withdrawn into the rigid sleeve 220.

The outer diameter of the curved needle 101 can be made non-uniform,being small at the distal end for creating a small opening, as shown inFIG. 72. The adjoining curved portion of the needle 101 contains a thickwall and a larger outer diameter to support and strengthen the processof endplate 105 puncturing. The transition between the small and largeouter diameters is gradual, as shown in FIG. 72, or in steps. The curvedneedle 101 with varying outer diameters can be made by grinding,machining or injection molding.

The lumen 268 of the rigid needle 220 may have a bevel 102 and adouble-sided ramp 272, as shown in FIG. 72. The bevel 102 or tapering atthe distal end of the lumen 268 minimizes friction against the concaveside of the curved needle 101 during deployment and retrieval. Thedouble-sided ramp 272 is protruded at the side opposite to the bevel 102with the distal side in continuation with the sharp tip or extended endof the rigid needle 101. The proximal side of the ramp 272 or protrusioncan be shaped to conform to and support the convex side of the curvedneedle 101 during endplate 105 puncturing. The ramp 272 can be made withepoxy, solder or other hardened material, then shaped by machining. Theramp 272 can also be created during a molten process to seal the lumen268 at the distal end. The sealed end is then cut, the ramp 272 andbevel 102 are shaped, and the lumen 268 is re-opened by machining.

Sections of the conduit 126 are made to optimize the exchange ofnutrients and waste. FIG. 73 shows a conduit 126 with braided filaments.In connected to a porous tube 125 with a lumen 104. The tubular 125portion acts as a funnel, collecting nutrients from capillaries withinthe vertebral body 159 and funneling the nutrients into braidedfilaments 122 within the nucleus pulposus 128.

Especially at the endplate 105, mineralization within the pores orchannels of the conduit 126 may occlude or block the exchange ofnutrients and waste between the vertebral body 159 and disc 100. FIG. 74shows a tube 125 covering or wrapped around the mid-section of theconduit 126 to prevent ingrowth of minerals or tissue into the pores orchannels. The material for making the tube 125 can also have swelling,expanding or sealing characteristics to seal the puncture at theendplate 105 and prevent formation of Schmorl's node. The swelling,expanding or sealing material can be polyethylene glycol, polyurethane,silicon or others. An anti-ingrowth film or coating at the mid-sectionof the conduit 126 may also discourage mineralization or occlusionwithin the channels or pores to ensure long lasting exchange ofnutrients and waste.

Especially within the vertebral body 159 or outer annulus, formation offibrous tissue over the conduit 126 may occur, hindering the exchange ofnutrient and waste. A portion of the conduit 126 can be coated, grafted,covalently bonded or ionic bonded with a drug to minimize fibrousformation. The drug can be actinomycin-D, paclitaxel, sirolimus,cell-growth inhibitor or fibrous tissue inhibitor.

Due to the soft or pliable characteristic, conduits 126 made withbraided filaments 122 are difficult to deploy with the retrieving needle101 and stationary plunger 109. A conduit 126 made with braided filamentcan be stiffened with water soluble agents, such as starch, collagen,hyaluronate, chondroitin, keratan or other biocompatible agents. Afterdeployment, the soluble stiffening agent dissolves within the body,exposing the filaments to transport nutrients, oxygen and waste. FIG. 75shows a monofilament 110 used as a stiff core within the braided conduit126 to assist deployment. The monofilament 110 can be made withdegradable material to maximize transport area after deployment of theconduit 126. Degradable tubes 125, indicated in the shaded area of FIG.76, can also be used to wrap and stiffen the braided filaments 122. Thedegradable tube 125 or the degradable monofilament 110 can be made withpoly-lactide, poly-glycolide, poly-lactide-co-glycolide or others.

Since nutrients are relatively abundant within the peripheral 1 cm ofthe disc 100, the conduit 126 can also draw nutrients from the outerannulus through capillary action into the nucleus pulposus 128. A needle101 carrying the starch-stiffened conduit 126 (not shown) and a plunger109 is punctured into a disc 100 with calcified endplates 105, as shownin FIG. 77. The needle 101 guiding technique is similar to the one usedin diagnostic injection of radiopaque dye for discography or chymopapaininjection for nucleus pulposus 128 digestion to treat herniated discs100. Guided by anteroposterior & lateral views from fluoroscopes, theneedle 101 enters posteriolaterally, 45° from mid-line into the disc100. A longitudinal view of the needle 101 crying the stiffened conduit126 puncturing through the disc 100 with calcified endplates 108 isshown in FIG. 78.

By holding the plunger 109 stationary while the needle 101 is beingwithdrawn, the conduit 126 is dislodged from the lumen of the needle 101and deployed across the disc 100, as shown in FIGS. 79-80. At least oneend of the conduit 126 is placed less than 1 cm from the periphery ofthe disc 100 to draw nutrients and drain lactic acid. To enhanceimaging, the section of the needle 101 containing the conduit 126 can becoated with a radiopaque, echogenic or magnetic coating 163, as shown inFIG. 81. Multiple conduits 126 can be safely and accurately deployedinto different areas of a degenerating disc 100. FIG. 82 shows twoconduits 126 deployed across a degenerating disc 100, exchangingnutrients and waste between the inner and outer disc 100.

In locations lacking any major blood vessel and organ, the tip of theneedle 101 can be guided beyond the disc 100, as shown in FIG. 83, todeploy the conduit 126 beyond the disc 100, as shown in FIG. 84. Theextended conduit 126 may draw significantly more nutrients into the disc100. In addition, the extended conduit 126 may be more effective indisposing the waste generated within the disc 100 and expediting therepair and/or regeneration of the disc 100, as shown in FIG. 85.

Psoas major muscles 193 are located adjacent to the lumbar segment ofthe spine. The needle 101 carrying the conduit 126 can puncture beyondthe disc 100 into the muscle 193. As a result, the conduit 126 can drawnutrients from the muscle 193 into the disc 100, as shown in FIG. 86.Muscles 193 are well supplied with nutrients and oxygen, and muscles 193dissipate lactic acid well. By extending into the muscles 193, theconduits 126 can draw an abundant amount of nutrients and safely depositthe waste from the inner disc 100 to repair or regenerate thedegenerating disc 100, as shown in FIG. 87. The supple and tensionlessconduits 126 are expected to be free from interfering with the functionsof the disc 100 and muscles 193.

Methods and devices for conduit 126 deployments can also be in variouscombinations. The conduits 126 can be delivered into the endplates 105,as shown in FIG. 53, and transverse the annulus, as shown in FIG. 82 or87.

An accelerated disc degeneration model was developed using rat tails. Atail section involving three discs was twisted or rotated 45° and heldfor 2 weeks. The section was then compressed by coil springs and heldfor an additional period of time. All discs within the sectiondegenerated. Discs that had received additional nucleus pulposus fromdonor discs by injection experienced a delay in degeneration.Furthermore, insertions of the additional nucleus pulposus prior to thedestructive loads provided the longest delay against disc degeneration.

After lumbar fusion procedures, the intervertebral discs 100 of adjacentfree motion segments degenerate quickly. The degenerative process leadsto more pain and possibly more surgery; following each new fusion is anew vulnerable segment adjacent to it. Accelerated degeneration ofsegments adjacent to a lumbar fusion may be the result of additionalpost-fusion stress and load. In the rat model, the added volume withinthe nucleus pulposus had a protective function against the destructiveload. In conjunction with spinal fusion procedures, implanting conduits126 within discs 100 adjacent to the fused segment may provide adequateswelling pressure contributed by an abundant supply of sulfate andoxygen to delay and hopefully prevent adjacent disc 100 degeneration.

Device migration with time is always a concern. The average age ofpatients undergoing back surgery is 40-45 years old. The conduit 126 isexpected to remain in place within the patients for fifty or more years.Migration of the tensionless conduits 126 may result in loss ofeffectiveness, but it is not likely to be detrimental to nerves,ligaments, muscles or organs. To minimize migration, knots 161 can betied on the braided conduit 126, as shown in FIG. 88, to anchor withinthe annulus, endplate 105 and/or muscle 193. Similar to knots 161, rings162 or protruded components 162 can be crimped on the conduit 126, asshown in FIG. 89. Both the knots 161 and the protrusions 162 are smallenough to fit within the needle 101. Tissue ingrowth can also limit orprevent device migration. Indentations 160 or tissue ingrowth holes 160can be created on the conduit 126, as shown in FIG. 90, to discouragemigration with time.

The conduit 126 can also be used as a delivery vehicle to introducehealing elements for maintaining or regenerating the disc 100. Theconduit 126 can be coated or seeded with growth factor, stem cells,donor cells, nutrients, buffering agent or minerals. Cells sensitive tosterilization can be loaded aseptically. Installations of conduits 126can be in multiple stages, separated by days, weeks, months or evenyears. Initial conduit 126 deployment prepares the biologicalconditions, including pH, electrolytic balance and nutrients, to favorcell proliferation. Subsequent deployments may contain seeded cellswithin the conduit 126.

Since cellularity within the inner disc 100 is low, cell migration fromthe outer annulus or vertebral bodies 159 can be helpful in regeneratingthe degenerating disc 100. Cells can be transported along the convectiveflow within the conduit 126 into the nucleus pulposus 128. The channelsor pores within the conduit 126, made with porous material, need to besufficiently large, about 50 to 200 microns. For minerals, nutrients,lactic acid and gas exchange alone, the channels or pore size can bemuch smaller. Hence, the useful range of the channel or pore size of theconduit 126 is about 200 microns to 10 nanometers.

Potentially useful coating for the conduit 126 include antibiotic,anti-occlusive coating, lubricant, growth factor, nutrient, sulfate,mineral, buffering agent, sodium carbonate, sodium bicarbonate,alkaline, collagen, hydroxyapatite, analgesic, sealant, humectant,hyaluronate, proteoglycan, chondroitin sulfate, keratan sulfate,glycosamino-glycans, heparin, starch, stiffening agent, radiopaquecoating, echogenic coating, cells or stem cells.

The tube 125 for preventing occlusion from mineralization or tissueingrowth can be made with a biocompatible polymer, such aspolytetrafluoroethylene, polypropylene, polyethylene, polyamide,polyester, polyurethane, silicon, poly-ether-ether-ketone, acetal resin,polysulfone, polycarbonate or polyethylene glycol. Similar material canbe used to coat or partially coat the conduit 126 to prevent blockage ofnutrient and waste transport. The coating should be able to withstandsterilization by gamma, electron beam, autoclave, ETO, plasma or UVlight to prevent infection.

Especially for investigative purposes, a biodegradable conduit 126 mayprovide evidence within weeks or months. Since the conduit 126 degradeswithin months, any unforeseen adverse outcome would be dissipated. Ifthe investigative-degradable conduit 126 shows promise, a permanentconduit 126 can then be installed to provide continuous benefits. Thebiodegradable conduit 126 can be made with polylactate, polyglycolic,poly-lactide-co-glycolide, polycaprolactone, trimethylene carbonate,silk, catgut, collagen, poly-p-dioxanone or combinations of thesematerials. Other degradable polymers, such as polydioxanone,polyanhydride, trimethylene carbonate, poly-beta-hydroxybutyrate,polyhydroxyvalerate, poly-gama-ethyl-glutamate, poly-DTH-iminocarbonate,poly-bisphenol-A-iminocarbonate, poly-orthoester, polycyanoacrylate orpolyphosphazene can also be used. Similar biodegradable material can beused to make the biodegradable monofilament 110 in FIG. 75.

A wide range of non-degradable materials can be used to fabricate theconduit 126. Biocompatible polymers, such as polytetrafluoroethylene,polypropylene, polyethylene, polyamide, polyester, polyurethane,silicon, poly-ether-ether-ketone, acetal resin, polysulfone,polycarbonate, silk, cotton, or linen are possible candidates.Fiberglass can also be a part of the conduit 126 to provide capillarityfor transporting nutrients and waste. Conduits 126 can also be made withmetal, such as nickel-titanium alloy or stainless steel. Bothnon-degradable and degradable conduits 126 can be formed by molding,extruding, braiding, weaving, coiling, spiraling or machining. Theconduits 126 can have a longitudinal lumen 104, pores and/or channelsfor fluid exchange. The conduit 126 can be a suture with a proven safetyrecord. The conduit 126 can also be called or classified as a shunt,wick, tube, braided suture, braided filaments, thread or sponge. Thedisc 100 with the conduits 126 installed can be called the shunted disc100.

The rigid needle 101, trocar 103, dilator 230 and plunger 109 can bemade with stainless steel or other metal or alloy. The elasticallycurved needle 101, shape memory extension 271 and plunger 109 can beformed with nickel-titanium alloy. The needle 101, rigid needle 220,dilator 230, shape memory extension 271 and plunger 109 can be coatedwith lubricant, tissue sealant, analgesic, antibiotic, radiopaque,magnetic and/or echogenic agents.

Since nutrients and oxygen are extremely low particularly indegenerating discs 100, cell death is common, and healthy cells capableof producing glycosaminoglycans are few. Healthy cells 277 can be drawnfrom another disc 100 within the patient to inject with a syringe 276into the degenerated disc 100, as shown in FIG. 91. Exchange ofnutrients and waste is reestablished through the newly installedconduits 126 through the cranial and caudal endplates 105 to nourishboth the donor cells 277 and the remaining cells within the degeneratingdisc 100. Similarly, donor cells 277 can also be injected into the disc100 with transverse conduits 126 to revitalize the disc 100, as shown inFIG. 92. Since cellularity within the degenerative disc 100 is low,introduction of donor cells 277 may expedite the process of halting orreversing disc degeneration.

The avascular disc 100 is well sealed. Even small ions, such as sulfate,and small molecules, such as proline, are greatly limited from diffusinginto the nucleus pulposus 128. The well sealed disc 100 may be able toencapsulate donor cells 277 from a disc 100 of another person, cadaveror animal without triggering an immune response. For disc 100regeneration, the donor cells 277 can also be stem cells 277, notochord277 or chondrocytes 277. The semi-permeable conduits 126 are permeableto nutrients and waste but impermeable to cells, proteins, glycoproteinsand/or cytokines responsible for triggering an immune reaction. Thecells of the immune system include giant cells, macrophages, mononuclearphagocyts, T-cells, B-cells, lymphocytes, Null cells, K cells, NK cellsand/or mask cells. The proteins and glycoproteins of the immune systeminclude immunoglobulins, IgM, IgD, IgG, IgE, other antibodies,interleukins, cytokines, lymphokines, monokines and/or interferons.

The molecular weights of nutrients and waste are usually much smallerthan the immuno-responsive cells, proteins and glycoproteins. Thetransport selectivity can be regulated or limited by the size of thepores or channels within the semi-permeable conduit 126, made withporous material. The upper molecular weight cut-off of the conduit 126can be 3000 or lower to allow the passage of nutrients and waste butexclude the immuno-responsive cells, proteins, immunoglobulins andglycoproteins. The semi-permeable conduit 126 may also contain ionic oraffinity surfaces to attract nutrients and waste. The surfaces of thesemi-permeable conduit 126 can be selected or modified to repel, excludeor reject immuno-responsive components.

In recent years, cell transplants from cadavers or live donors have beensuccessful in providing therapeutic benefits. For example, islet cellsfrom a donor pancreas are injected into a type I diabetic patient'sportal vein, leading into the liver. The islets begin to function asthey normally do in the pancreas by producing insulin to regulate bloodsugar. However, to keep the donor cells alive, the diabetic patientrequires a lifetime supply of anti-rejection medication, such ascyclosporin A. In addition to the cost of anti-rejection medication, thelong-term side effects of these immuno-suppressive drugs are uncertain.The benefit of cell transplant may not out weigh the potential sideeffects.

The intervertebral disc 100 with semi-permeable conduits 126 can be usedas a semi-permeable capsule to encapsulate therapeutic donor cells 277or agents, as shown in FIGS. 91 and 92, and evade the immune response;hence no life-long immuno-suppressive drug would be required. A varietyof donor cells 277 or agent can be harvested and/or cultured from thepituitary gland (anterior, intermediate lobe or posterior),hypothalamus, adrenal gland, adrenal medulla, fat cells, thyroid,parathyroid, pancreas, testes, ovary, pineal gland, adrenal cortex,liver, renal cortex, kidney, thalamus, parathyroid gland, ovary, corpusluteum, placenta, small intestine, skin cells, stem cells, gene therapy,tissue engineering, cell culture, other gland or tissue. The donor cells277 are immunoisolated within the discs 100, the largest avascularorgans in the body, maintained by nutrients and waste transport throughthe semi-permeable conduits 126. The donor cells 277 can be from human,animal or cell culture. In the supine sleeping position, nutrients andoxygen are supplied through the conduits 126 to the donor cells 277.During waking hours while the pressure within the disc 100 is high,products biosynthesized by these cells 277 are expelled through theconduit 126 into the vertebral bodies 159, outer annulus or muscle 193,then into the veins, bodily circulation and target sites.

The product biosynthesized by the cells 277 within the shunted disc 100can be adrenaline, adrenocorticotropic hormone, aldosterone, androgens,angiotensinogen (angiotensin I and II), antidiuretic hormone,atrial-natriuretic peptide, calcitonin, calciferol, cholecalciferol,calcitriol, cholecystokinin, corticotropin-releasing hormone, cortisol,dehydroepiandrosterone, dopamine, endorphin, enkephalin, ergocalciferol,erythropoietin, follicle stimulating hormone, γ-aminobutyrate, gastrin,ghrelin, glucagon, glucocorticoids, gonadotropin-releasing hormone,growth hormone-releasing hormone, human chorionic gonadotrophin, humangrowth hormone, insulin, insulin-like growth factor, leptin, lipotropin,luteinizing hormone, melanocyte-stimulating hormone, melatonin,mineralocorticoids, neuropeptide Y, neurotransmitter, noradrenaline,oestrogens, oxytocin, parathyroid hormone, peptide, pregnenolone,progesterone, prolactin, pro-opiomelanocortin, PYY-336, renin, secretin,somatostatin, testosterone, thrombopoietin, thyroid-stimulating hormone,thyrotropin-releasing hormone, thyroxine, triiodothyronine, trophichormone, serotonin, vasopressin, or other therapeutic products.

The products (hormones, peptides, neurotransmitter, enzymes, catalysisor substrates) generated within the shunted disc 100 may be able toregulate bodily functions including blood pressure, energy,neuro-activity, metabolism, activation and suppression of glandactivities. Some hormones and enzymes govern, influence or controleating habits and utilization of fat or carbohydrates. These hormones orenzymes may provide weight loss or gain benefits. Producingneurotransmitters, such as dopamine, adrenaline, noradrenaline,serotonin or γ-aminobutyrate, from the donor cells 277 within theshunted disc 100 can treat depression, Parkinson's disease, learningdisability, memory loss, attention deficit, behavior problems, metal orneuro-related disease.

Release of the products biosynthesized by the donor cells 277 within theshunted disc 100 is synchronized with body activity. During activitiesof daily living, the pressure within the shunted disc 100 is mostly highto expel the products biosynthesized by the donor cells 277 intocirculation to meet the demands of the body. In the supine position, theflow within the shunts 126 is reversed, bringing nutrients and oxygeninto the disc 100 to nourish the cells 277. Using islets of Langerhansfrom the donor's pancreas as an example, production of insulin isinduced in the shunted disc 100 during sleeping hours when glucoseenters into the disc 100. During waking hours when disc pressure ishigh, insulin is expelled through the conduits 126 into circulation todraw sugars into cell membranes for energy production. At night, theinsulin released from the shunted disc 100 is minimal to prevent thehypoglycemia. In essence, products biosynthesized by the donor cells 277are released concurrent with physical activity to meet the demands ofthe body.

Some biosynthesized products from the donor cells 277 are appropriatelydeposited through the vertebral body 159, as shown in FIG. 91, then intobodily circulation. Other products may be more effectively transportedthrough the outer annulus, as in FIG. 82, and diffused through theabdomen into bodily circulation. Some other products may be far moreeffective by entering into the muscles 193, as shown in FIG. 92.

Growth factors, buffering agents, hormones, gene therapeutic agents,nutrients, minerals, analgesics, antibiotics or other therapeutic agentscan also be injected into the shunted discs 100, similar to FIGS. 91-92.

It is to be understood that the present invention is by no means limitedto the particular constructions disclosed herein and/or shown in thedrawings, but also includes any other modification, changes orequivalents within the scope of the claims. Many features have beenlisted with particular configurations, curvatures, options, andembodiments. Any one or more of the features described may be added toor combined with any of the other embodiments or other standard devicesto create alternate combinations and embodiments. The conduit 126 canalso have a gate to regulate rate and/or flow direction of nutrient, gasand waste exchange. It is also possible to connect a pump to the conduit126 to assist the exchange between the disc 100 and the bodily fluid. ApH electrode may be exposed near the tip of the rigid needle 220 todetect the acidity within the disc 100.

It should be clear to one skilled in the art that the currentembodiments, materials, constructions, methods, tissues or incisionsites are not the only uses for which the invention may be used.Different materials, constructions, methods or designs for the conduit126 can be substituted and used. Nothing in the preceding descriptionshould be taken to limit the scope of the present invention. The fullscope of the invention is to be determined by the appended claims. Forclarification in claims, sheath is a rigid tubular member. Theelastically curved needle 101 can be called the elastic needle.

1. A deployment device for deploying a conduit into an intervertebraldisc, the deployment device comprising: a tubular sheath for puncturingthe intervertebral disc, a conduit, wherein said conduit is sized andconfigured to fit at least partially within said tubular sheath, andwherein said conduit has a first end and a second end, and a plungersized to at least partially fit within said tubular sheath and designedto deploy said conduit, said deployment device having a first positionwherein said conduit is located at least partially within said tubularsheath, and said deployment device having a second position wherein saidconduit has been expelled from said tubular sheath and wherein saidfirst end is implanted into the intervertebral disc, and said second endof said conduit is implanted into a muscle, thereby re-establishingexchange of waste and nutrients between the intervertebral disc andmuscle.
 2. The deployment device of claim 1, wherein said tubular sheathhas a beveled tip.
 3. The deployment device of claim 1, furthercomprising a needle located at least partially within said tubularsheath.
 4. The deployment device of claim 3, wherein said conduit islocated at least partially within said needle.
 5. The deployment deviceof claim 3, wherein said conduit is located at least partially aroundsaid needle.
 6. The deployment device of claim 1, further comprising acoating on said tubular sheath.
 7. The deployment device of claim 6,wherein the coating is chosen from the group of coatings consisting oflubricant, tissue sealant, analgesic, antibiotic, radiopaque, magneticand echogenic agents.
 8. The deployment device of claim 1, wherein saidconduit is a tube formed of a biocompatible material.
 9. The deploymentdevice of claim 1, wherein said conduit is a multi-filament formed of abiocompatible material.
 10. The deployment device of claim 1, whereinsaid conduit is a sponge formed of a biocompatible material.
 11. Thedeployment device of claim 1, wherein said conduit has a plurality ofprotrusions extending therefrom.
 12. The deployment device of claim 11,wherein said protrusions are chosen from the group consisting offlanges, knots and rings.
 13. The deployment device of claim 1, whereinsaid conduit is formed of a multi-filament portion and a mono-filamentportion.
 14. The deployment device of claim 1, wherein said conduit isformed of a biodegradable material.
 15. The deployment device of claim1, wherein said conduit is formed of a non-degradable material.
 16. Thedeployment device of claim 1, wherein said conduit is formed of anon-degradable material chosen from the group of materials consisting ofpolytetrafluoroethylene, polypropylene, polyethylene, polyamide,polyester, polyurethane, silicon, poly-ether-ether-ketone, acetal resin,polysulfone, polycarbonate, silk, cotton, linen, fiberglass,nickel-titanium alloy and stainless steel.
 17. The deployment device ofclaim 1, wherein said conduit is formed of a degradable material chosenfrom the group of materials consisting of polylactate, polyglycolic,poly-lactide-co-glycolide, polycaprolactone, trimethylene carbonate,silk, catgut, collagen, poly-p-dioxanone, polydioxanone, polyanhydride,trimethylene carbonate, poly-beta-hydroxybutyrate, polyhydroxyvalerate,poly-gama-ethyl-glutamate, poly-DTH-iminocarbonate,poly-bisphenol-A-iminocarbonate, poly-ortho-ester, polycyanoacrylate andpolyphosphazene.
 18. The deployment device of claim 1, wherein saidconduit has a coating chosen from the group of coatings consisting ofantibiotic, anti-occlusive coating, lubricant, growth factor, nutrient,sulfate, mineral, buffering agent, sodium carbonate, sodium bicarbonate,alkaline, collagen, hydroxyapatite, analgesic, sealant, humectant,hyaluronate, proteoglycan, chondroitin sulfate, keratan sulfate,glycosamino-glycans, heparin, starch, stiffening agent, radiopaquecoating, echogenic coating, gene, cells and stem cells.
 19. Thedeployment device of claim 1, wherein said conduit is porous and has apore size of 200 microns to 10 nanometers.
 20. The deployment device ofclaim 1, wherein said conduit is porous and has channels therethrough,said channels having a diameter of 200 microns to 10 nanometers.
 21. Thedeployment device of claim 1, further comprising a tube located around acentral portion of said conduit.
 22. The deployment device of claim 21,wherein said tube is formed of a material chosen from the group ofmaterials consisting of polytetrafluoroethylene, polypropylene,polyethylene, polyamide, polyester, polyurethane, silicon,poly-ether-ether-ketone, acetal resin, polysulfone, polycarbonate andpolyethylene glycol.
 23. The conduit of claim 1, wherein at least aportion of said conduit is coated with fibrous tissue inhibitor.
 24. Thedeployment device of claim 1, wherein in said second position, saidtubular sheath is located outside the intervertebral disc.
 25. Thedeployment device of claim 1, wherein said conduit is a linear porousfilament.
 26. A deployment device for deploying a conduit into anintervertebral disc, the deployment device comprising: a tubular sheathfor puncturing the intervertebral disc, a first elastic needle having astraightened position and a curved position, said straightened positionbeing elastically straightened within said tubular sheath, and saidcurved position being elastically curved and located at least partiallyoutside said tubular sheath, an actuator to moved said first elasticneedle between said straightened position and said curved position, anda conduit sized and configured to fit at least partially within saidtubular sheath, wherein said conduit has a first end and a second end,said deployment device having a first position wherein said conduit islocated at least partially within said tubular sheath, and saiddeployment device having a second position wherein said conduit has beenexpelled from said tubular sheath and wherein said first end isimplanted into the intervertebral disc, and said second end is implantedinto a muscle, thereby re-establishing the exchange of waste andnutrients between the intervertebral disc and muscle.
 27. The deploymentdevice of claim 26, wherein said first elastic needle has a beveled tip.28. The deployment device of claim 27, wherein a point of said beveledtip is located on a concave side of said first elastic needle, when saidfirst elastic needle is in said curved position.
 29. The deploymentdevice of claim 26, wherein said tubular sheath has a sharp tip.
 30. Thedeployment device of claim 29, wherein said sharp tip is oriented on aconvex side of said first elastic needle, when said first elastic needleis in said curved position.
 31. The deployment device of claim 26,wherein said tubular sheath and said first elastic needle have non-roundcross sections.
 32. The deployment device of claim 31, wherein saidtubular sheath and said first elastic needle have similarcross-sectional shapes.
 33. The deployment device of claim 26, whereinsaid tubular sheath and said first elastic needle have oval crosssections.
 34. The deployment device of claim 26, further comprising asecond elastic needle, said second elastic needle located at leastpartially around said first elastic needle.
 35. The deployment device ofclaim 34, wherein said first and second elastic needles have similarcurvatures and said curvatures are oriented in similar directions. 36.The deployment device of claim 26, further comprising an openingextending through a wall of said tubular sheath proximate a distal endthereof.
 37. The deployment device of claim 26, wherein said tubularsheath has a ramp located therein.
 38. The deployment device of claim37, wherein said ramp is located proximate a distal end of said tubularsheath and located proximate a convex side of said first elastic needle.39. The deployment device of claim 26, wherein said first elastic needleis formed of nickel-titanium alloy.
 40. The deployment device of claim26, wherein said first elastic needle has a non-uniform cross-section.41. The deployment device of claim 40, wherein said first elastic needlehas a distal end and a proximal end, said distal end being smaller thansaid proximal end.
 42. The deployment device of claim 26, furthercomprising a plunger for deploying said conduit.
 43. The deploymentdevice of claim 26, further comprising a coating on said tubular sheath.44. The deployment device of claim 43, wherein the coating is chosenfrom the group of coatings consisting of lubricant, tissue sealant,analgesic, antibiotic, radiopaque, magnetic and echogenic agents. 45.The deployment device of claim 26, further comprising a coating on saidfirst elastic needle.
 46. The deployment device of claim 45, wherein thecoating is chosen from the group of coatings consisting of lubricant,tissue sealant, analgesic, antibiotic, radiopaque, magnetic andechogenic agents.
 47. The deployment device of claim 26, wherein saidconduit is a tube formed of a biocompatible material.
 48. The deploymentdevice of claim 26, wherein said conduit is a multi-filament formed of abiocompatible material.
 49. The deployment device of claim 26, whereinsaid conduit is a sponge formed of a biocompatible material.
 50. Thedeployment device of claim 26, wherein said conduit has a plurality ofprotrusions extending therefrom.
 51. The deployment device of claim 26,wherein said conduit is formed of a multi-filament portion and amono-filament portion.
 52. The deployment device of claim 26, wherein insaid first position, wherein said conduit is located within said firstelastic needle.
 53. The deployment device of claim 26, wherein in saidfirst position, wherein said conduit is located at least partiallyaround said first elastic needle.
 54. The deployment device of claim 26,wherein said conduit has a coating chosen from the group of coatingsconsisting of antibiotic, anti-occlusive coating, lubricant, growthfactor, nutrient, sulfate, mineral, buffering agent, sodium carbonate,sodium bicarbonate, alkaline, collagen, hydroxyapatite, analgesic,sealant, humectant, hyaluronate, proteoglycan, chondroitin sulfate,keratan sulfate, glycosamino-glycans, heparin, starch, stiffening agent,radiopaque coating, echogenic coating, gene, cells and stem cells. 55.The deployment device of claim 26, wherein said conduit is porous andhas a pore size of 200 microns to 10 nanometers.
 56. The deploymentdevice of claim 26, wherein said conduit is porous has channelstherethrough, said channels having a diameter of 200 microns to 10nanometers.
 57. The deployment device of claim 26, further comprising atube located around a central portion of said conduit.
 58. Thedeployment device of claim 26, wherein in said second position, saidfirst elastic needle is locatable outside of the intervertebral disc.